This invention relates to a leather-covered steering wheel, particularly to a leather-covered steering wheel comprising a metal core including a plurality of spoke core sections and a ring core section, an elastic cover layer for covering the ring core section and the end portions of the spoke core sections at the side of the ring core section, and a leather for covering the elastic cover layer.
In a conventional leather-covered steering wheel, the ring core section of the metal core and the end portions of a plurality of spoke core sections of the metal core thereof at the side of the ring section are formed to be covered with an elastic cover layer of highly foamed urethane. Further, the elastic cover layer is covered with a leather such as natural leather or synthetic leather with a sponge-like chloroprene rubber material held therebetween (cf. Japanese Patent Application Examined Publication No. 21579/1978 and USP 3,802,291).
In the conventional leather-covered steering wheel, the elastic cover layer has some degree of hardness, 65 to 80 in the degree of hardness (ASTM, shore hardness A). Therefore, the steering wheel is free from a difficulty that the corners of the portions of the elastic cover layer which portions are on the side of the end faces are deformed, or greatly curved, even if the elastic cover layer is covered with the leather while tension is applied to the leather by sewing the leather together with string.
On the other hand, in order to reduce the number of manufacturing steps and the manufacturing cost of the conventional leather-covered steering wheel, the following method has been employed. The use of chloroprene rubber material is eliminated, instead, in order to maintain substantially unchanged the soft feeling with the ring section when gripped, or to make it softer, an elastic cover layer lower in hardness (35 to 65 in the degree of hardness (ASTM, Shore hardness A)) is employed. In this case, since the elastic cover layer is soft, when it is covered with the leather under such a condition that tention is applied to the leather by sewing the leather together with string, the corners of the portions of the elastic cover layer which are on the side of the end faces are liable to be deformed, with the result that the steering wheel is degraded in external appearance.